Inclusion criteria, exclusion criteria and study summary
Myelofibrosis (MF) is a cancer of the bone marrow that disrupts the production of blood cells. Symptoms of MF include anaemia (low red cell levels), weakness, tiredness and often an enlarged spleen. Standard treatment can involve chemotherapy, radiotherapy, a stem cell transplant or treatment with a drug called ruxolitinib. Ruxolitinib targets the specific cells that play a part in the development of MF, and is the only drug licenced to treat MF. Previous research has shown that ruxolitinib is good at reducing symptoms of MF and decreasing the size of the spleen. However, the majority of patients do not show a complete response to ruxolitinib, meaning that another treatment needs to be added to ruxolitinib to improve the outcome for patients. This study will test whether combining ruxolitinib with another drug called a bromodomain and extra terminal inhibitor (BETi) is safe for MF. Research has suggested that combining these two drugs will have a clinical benefit to patients. The main aims of the study are to find a suitable dose of PLX2853 when combined with ruxolitinib, and investigate the safety by looking at the side effects of treatment, and to see how well the combination treats MF.